1. Field of the Invention
The invention relates to an endoscope and, more particularly, to a frame of a deflection section of an endoscope.
2. Brief Description of Prior Developments
U.S. Patent Publication No. 2005/0245789 A1 discloses an endoscope having a shaft frame with pivotably connected members. There is a conventional endoscope shaft riveted deflection system construction that consists of a number of deflection rings connected together with rivets. Each rivet has a first head. Each rivet is inserted into corresponding holes of joining rings from inside the deflection system, and then a second head is formed from outside during the assembly.
There is another riveted deflection construction used in a Storz Flex-X Flexible Ureteroscope where the cylindrical body of each rivet is welded to an inner ear flat surface of one of the deflection rings, and each rivet has only one head located outside the deflection system frame. The conventional construction having a rivet with two heads is less torque resistant than the Storz construction; due to the clearance between the rivet body and the two deflection ring holes. In the conventional construction having a rivet with two heads it is difficult to control rivet cylindrical body dimensions (of the rivet shaft section) to maintain guaranteed clearance between the rivet head and the two deflections rings due to the force applied to form the second rivet head. In the Storz construction, it is difficult to maintain guaranteed clearance due to welding the rivet to the inner ear flat surface of one of the deflection rings because the welding process requires pressing the rivet to the ring ear flat surface by force, this can deform the ring which can result in a clearance problem remaining after welding. Thus, there is a desire to provide a different method of manufacture and resultant shaft frame which has better guaranteed clearance among the rivet and frame rings.